Air conditioning apparatus



'Au .2o, 1940. I HOLMES 2,211,930-

AIR CONDITIONING APPARATUS Filed Dec. 1, 1936 WITNESSES: 1-o INVENTOR ATTOR Patented-Aug. 20, 1940 umrsn STATES AIR CONDITIONING APPARATUS Richard E. Holmes, Springfield, Mass., assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 1, 1936, Serial No. 113,558

8 Claims.

My invention relates to air conditioning apparatus, more particularlyto a self-contained unit air cooler or conditioner. Such apparatus usually includes, among other elements, an evaporator for cooling air by direct contact therewith, a drip pan and a drain pipe for collecting and removing the moisture condensed from the air, a motor compressor unit for compressing refrigerant, and a suction conduit for conveying the vaporized refrigerant from the evaporator to the motor compressor unit. The suction conduit, and also the drain pipe as arranged prior to my invention, are at sufficiently low temperature to condense moisture from the air, so that these pipes are usually covered with heat insulating material to prevent such condensation or sweating.

It is an object of my invention, broadly, to provide improved apparatus.

A particular object is to avoid the necessity of heat insulating the suction conduit or the drain pipe.

A further object is to arrange the suction conduit so that the moisture condensed thereon is collected and conveyed to the drain pipe, so as to render condensation of moisture on the suction conduit unobjectionable.

Another object is to prevent condensation or sweating of the drain pipe.

A further object is to increase the efficiency of the air cooling mechanism, more particularly by utilizing the cooling effect available in the moisv ture condensed from the air at low temperature.

In accordance with my invention, 1 provide the drip pan with an outlet opening for gravity flow of the collected moisture therefrom. A receptacle in heat, conducting relation to the motor compressor unit is disposed directly beneath said opening to receive the moisture therefrom. The moisture is heated in the receptacle by heat from the motor compressor unit, thereby effecting cooling of the latter and increasing the cooling capacity of the apparatus. The heated moisture is then removed. through a drain pipe. The suction conduit extends from the evaporator through the outlet opening and the receptacle to the motor compressor unit, being arranged above the moisture collecting elements so that condensation on the suction conduit becomes unobjectionable.

The above mentioned and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a vertical section of a unit air cooler embodying my invention; and

Fig. 2 is an enlarged fragmentary view of the novel portion of the apparatus in slightly modified form.

Referring to the drawing in detail, the unit air cooler or conditioner shown in Fig. 1 includes a casing II, which may be of any suitable construction and isshown in the present embodiment as comprising a frame having vertical members I2 and horizontalmembers I3. The casing further includes vertical walls I4 spaced from the frame and a top wall I5 having a discharge opening I6, resting on the top of the frame. An evaporator I! is mounted on the vertical frame members I2 in the upper portion of the unit and may be of any suitable form. As shown, it comprises a cross-finned coil having horizontal tubes I8 connected by the usual U-bends I9 and transverse fins or blades 20 providing extended heat transfer surfaces. A fan 2I is mounted above the evaporator for effecting flow of air upwardly over the surfaces of the evaporator, and through a duct member 23, a shroud 22 and the discharge opening I6 into the room in which the unit is placed.

A drip pan 24, disposed directly beneath the evaporator and supported on the horizontal frame members I3, serves tocollect the moisture con-v densed on the surfaces of the evaporator. It has an upwardly extending flange 25 extending along the edge thereof, and it is formed with an outlet 26 in the bottom thereof through which the collected moisture is drained. A flange 21 projects downwardly from the edge of the opening 26.

A motor compressor unit 28 is disposed beneath the drip pan 24 and the outlet opening 26. It may be supported in any suitable manner, as by suspending the same from the horizontal frame members I3, for which purpose the brackets 29 may be provided. In the present embodiment, the motor-compressor unit is of the hermetically sealed type, including a casing 30 that encloses the compressor and the motor driving the same (not shown).

The casing 30 is formed with a receptacle 3|, disposed directly beneath the opening 26 and telescoping the fiange 21, for receiving the moisture drained from the outlet opening 26. As shown in Fig. 1, it is formed by a tubular member 32 extending vertically through an opening in the casing and a disk member 33 forming a bottom for the receptacle 'and'a closure for the opening in 3| for removing the moisture therefrom, and it includes a horizontal portion 35 and a vertical portion 36 connected by a T-fitting 31. An opening normally closed by a plug 39 is formed in the T-fitting 31 in alinement with the horizontal portion 35 for the purpose of enabling a cleaning tool to be inserted in the horizontal portion and into the receptacle 3| to clean the same of foreign matter that may collect therein. The T-fitting 31 is formed with anopening 33 in the top thereof, for a purpose hereinafter described. The opening is at a lower level than the top of the receptacle 3|.

In accordance with the present invention, the suction conduit 4|, which conveys the vaporized refrigerant from the evaporator I! to the motorcornpressor unit 28, extends downwardly through the outlet opening 26, and the interior and the bottom of the receptacle 3| into the interior of the casing 3|]. It terminates in a strainer fitting 40, through which the vaporized refrigerant is discharged into the interior of the casing 30. In the illustrated embodiment, a reservoir 42 is connected in the suction conduit 4| for the purpose of retaining any unvaporized refrigerant that may be discharged from the evaporator. The portion of the suction conduit between the outlet of the evaporator and the opening 26 including the reservoir 42, is disposed entirely above the drip pan 24, so that any moisture formed thereon is collected by the drip pan.

The apparatus further includes the remaining elements of a conventional mechanical refrigerating system. The condenser 43 may be, as shown, of the double tube, water-cooled type, and supported on brackets 44 fixed to the casing 30. The compressed refrigerant is conveyed from the motor-compressor unit to the condenser through a conduit 45. The condensed refrigerant is conveyed through a conduit 46 (only partly shown) to a float valve chamber 41, from which it is conveyed through a conduit 48 to the evaporator H. The cooling water leaving the condenser 43 is conveyed .through a cooling coil 49 encircling the casing 30 for the purpose of removing the motor and compressor heat from the unit 28. A housing 5|, lined with heat. insulating material 52, is preferably provided for enclosing the motor-compressor unit and the condenser. The pipe 35 extends through the housing BI, and the T-fitting 31 is located on the exterior thereof.

Operation The air to be cooled is conveyed to the evaporator IT in any suitable manner and, in the present embodiment, it passes around the lower edges of the vertical walls M, upwardly between said walls and the horizontal members l3, then through the space between the evaporator and the drip pan, over the surfaces of the evaporator, past the fan and through the duct portion 23, the shroud 22 and the outlet l6 into the room or enclosure in which the unit is positioned.

The refrigerating system operates in the usual manner for cooling the air as it comes in contact with the evaporator. The refrigerant is compressed in the motor-compressor unit 28, then condensed in the condenser 43, and admitted under control of the float valve 41 to the evaporator H. The refrigerant vaporized in the evaporator I! is conveyed through the suction conduit 4| and the reservoir 42 to the motor-con pressor unit 28, being admitted to the interior of the casing 30. Any unvaporized refrigerant is retained in the reservoir 42.

The evaporator I1 is maintained at a sufllcient-, ly low temperature to condense moisture from the air. The moisture falls from the evaporator I and is collected by the drip pan 24, from which it is drained through the opening 26 into the receptacle 3| The receptacle 3| is in good heat conducting relation to the motor and compressor within the casing 30. Thus, there is an effective flow of heat from the motor and the compressor to the receptacle 3|. Such transfer of heat may be facilitated by directing a stream of oil against the receptacle. Accordingly, the moisture, which is condensed at relatively low temperature, is subjected to the relatively high temperature of the motor-compressor -unit and is thus able to absorb a substantial quantity of heat therefrom. The removal of this heat from the motor-compressor unit increases the capacity of the refrigerating system to remove heat from the air passing over the evaporator IT.

The heated moisture then flows by gravity through the drain pipe 34. Inasmuch as its temperature is now above the dew point of the air, it does not effect condensation of moisture on the pipe 34. Thus, any possibility of sweating is eliminated.

In the event that the drain pipe 36 becomes clogged, the water spills through the opening 38 onto the floor outside of the housing 5|, where it will be more readily detected. If this opening were not provided, the water would overflow the receptacle 3| when the pipe becomes clogged, and spill into the inside of the housing 5|, where it would damage the insulation 52 before it would be detected.

The moisture condensed on the suction conduit 4| is collected and drained by the drip pan 2d and the receptacle 3|, so that such condensation or sweatingis rendered unobjectionable.

In Fig. 2, I show an embodiment of my invention in which the form of the receptacle is modified but whose operation is essentially the same as that of Fig. 1. In this case, the lower end of the tubular member 32' isturned inwardly to form a bottom 33' for the receptacle. The T- fitting 3'! is essentially the same as the T-fitting 31 of Fig. 1.

From the above description, it will be seen that I have provided a unit air cooler wherein the moisture formed on the suction conduit is collected and drained so as to avoid any objection to such condensation or sweating; wherein the moisture is heated before being admitted to the drain conduit so that sweating of the drain conduit is eliminated; and wherein the cooling effect of the moisture is utilized to remove heat from the refrigerating system, whereby its capacity to remove heat from the air is increased.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In a unit air cooler, the combination of an evaporator, a drip pan disposed beneath said evaporator for receiving moisture condensed from the air and having an outlet opening formed therein, a. motor compressor unit having a casing enclosing the same and disposed beneath said drip pan, said casing having a receptacle formed therein immediately below said discharge opening to receive the moisture therefrom by gravity of flow, whereby the moisture is heated by heat from the motor-compressor unit, a suction conduit eigtending from said evaporator, through said outlet opening and said receptacle to the motor-compressor casing, whereby the moisture condensed on said suction line is collected in said receptac1e,.and means for removing moisture from said receptacle.

2. In a unit air cooler, the combination of an evaporator for cooling and dehumidifying air, a drip pan beneath the evaporator for collecting the moisture condensed from the air and having an outlet opening, a motor compressor unit having a receptacle in heat conducting relation therewith disposed directly below said outlet opening, a suction conduit extendingfrom said evaporator, through said outlet opening and said receptacle to said motor-compressor unit, the portion of the suction conduit between the evaporator and the outlet opening being disposed above the drip pan so that moisture formed on said conduit may be collected by said drip pan, and means for removing moisture from said receptacle.

3. In a unit air cooler, the combination of an evaporator for cooling and dehumidifying air, a drip pan beneath the evaporator for collecting the moisture condensed from the air and having an outlet opening, a motor compressor unit disposed below said drip pan, a suction conduit extending from said evaporator, through said outlet opening to said motor-compressor unit, the portion of the suction conduit between the evaporator and the outlet opening being disposed above the drip pan so that moisture formed on said conduit is collected by said drip pan, and means for disposing of the moisture draining through said outlet opening.

4. In a unit air cooler, the combination of a refrigerating system including an evaporator for cooling and dehumidifying air, a drip pan disposed beneath said evaporator for receiving the moisture condensed from the air and having an outlet opening, a receptacle disposed beneath said outlet opening to receive the moisture there- 'from by gravity flow and arranged in heat conreceiving the moisture condensed from the air and having an outlet opening, a compressor, a receptacle disposed beneath said outlet opening to receive the moisture therefrom by gravity flow and arranged in heat conducting relation with said compressor, and means for conveying vaporized refrigerant from said evaporator to said compressor including a suction conduit extending from said evaporator and through said outlet opening and said receptacle, whereby the moisture condensed on said suction line is collected in said receptacle.

6. In a unit air cooler, the combination of an evaporator for cooling and dehumidifying air, a drip pan disposed. beneath said evaporator for receiving the moisture condensed from the air and having an outlet opening, a compressor, a motor for driving the compressor, a receptacle disposed beneath said outlet opening to receive the moisture therefrom by gravity flow and arranged in heat conducting relation with said motor, and means for conveying vaporized refrigerant from said evaporator to said compressor including a suction conduit extending from said evaporator and through said outlet opening and said receptacle, whereby the moisture condensed on said suction line is collected in said receptacle.

7. In a unit air cooler, the combination of an evaporator for cooling and dehumidifying air,

' a drip pan beneath the evaporator for collecting the moisture condensed from the air and having an outlet opening, a motor compressor unit disposed below said outlet opening, a suction conduit extending from said evaporator, through said outlet opening to said motor-compressor unit, the portion'of the suction conduit between the evaporator and the outlet opening being disposed above the drip pan so that moisture formed on said conduit is collected by said drip pan, and means providing gravity flow of said moisture from said outlet in heat transfer relation with said motor-compressor unit and then discharging the same.

8. In a unit air cooler, the combination of an evaporator for cooling and dehumidifying air, a drip pan beneath the evaporator for collecting the moisture condensed from the air and having an outlet opening, a motor compressor unit disposed below said drip pan, a suction conduit extending from said evaporator, through said outlet opening to said motor-compressor unit, the portion of the suction conduit between the evaporator and the outlet opening being dis-' posed above the drip pan so that moisture formed on said conduit is collected by said drip pan, and a receptacle disposed beneath said outlet opening and the portion of the suction conduit between the outlet opening and motor-compressor unit to collect moisture therefrom.

RICHARD E. HOLMES. 

